1. Field of the Invention
The present invention relates to a device for detecting an opening or closing of a double door constituted by two sectional doors which meet together at swingable ends thereof and a tool to be used for the detecting device.
2. Description of Related Art
Such operations as exchange of a medium or an ink ribbon are frequently performed in, for instance, an automatic ticket selling machine. Sometimes jamming also occurs, which requires periodical maintenance of the machine. In this case, the door is opened to check inside of the machine, and necessary measures for trouble shooting are taken.
When the door is opened, a larger aperture is better from a viewpoint of workability. If, however, the door is a one-sheet door, a large space is required for its installation. So as to reduce a space required for installation, there is provided a double door which is divided into two leaves and the two leaves are swingable in the opposite directions from each other while meeting together at the center of the opening so as to close the opening.
If, in the structure of this type of door, a machine is run in the state where the door is kept open, sometimes the user may be injured or a foreign material may enter inside of the machine, which may in turn cause a malfunction. To prevent the troubles as described above, there have been proposed various types of machines which can detect that the door is opened and generate an alarm, or which incorporates a safety device to prevent the machine from being driven even if an operation for starting the machine is executed.
To provide the safety device as described above, there has been known a door opening/closing detecting device in which a mechanical switch for detecting an opening or closing of a door is fixed at an appropriate place in an inner side of the door, and an actuator lever of the mechanical switch is actuated by a bracket provided in an inner side of at least one of the two portions of the door to obtain a detection signal indicating whether the door is open or closed.
In the conventional type of door opening/closing detector as described above, there have been the problems as described in paragraphs (1) to (6) below.
(1) An actuator lever of a switch directly abuts onto a bracket attached to the door, so that the door vibrates due to internal or external vibration to easily cause a malfunction of the switch, which results in lower reliability and is liable to induce other troubles.
(2) An actuator level of a switch directly abuts onto a bracket attached to the door, so that the switch may be damaged when a physical shock is directly loaded to the switch from the outside.
(3) Even if one leaf which abuts onto the actuator lever of a switch is closed, another switch may be switched to enable start of the machine's operation, so that the sometimes operation of the machine may be started, while the user's hand is still inside the machine, and the user may be injured.
(4) As a method of solving the problem (3) described above, it is conceivable to provide a switch for each leaf of the double door, namely two switches for both leaves of the double door in all. If, however, a switch is provided for each leaf of the double door, addition of connectors, addition of wiring patterns and/or the like are required in the side of the substrate in association with the increase in a number of switches, which causes substantial increase of cost.
(5) In order to make sure that a bracket attached to the leaf pushes the switch, the actuator lever and the switch are provided at positions adjacent to the leaf. For this reason, the switches or the like can easily be seen when the door is opened, the user can easily push the switches or the like, and when the switches or the like are carelessly pushed, the user may be injured. This type of structure is not authorized in, for example, the UL standard (standards authorized by Underwriters Laboratories Inc.).
(6) As described in (4) above, even in the structure in which a switch is provided for each leaf of a double door, sometimes the two switches may simultaneously be pressed in some circumstances, and the problem similar to that described in (5) above may occur.